Network model for the viscoelastic behavior of polymer nanocomposites

Sarvestani, Alireza S.; Picu, Catalin R.

doi:10.1016/j.polymer.2004.08.060

Cited by 111 publications

(63 citation statements)

References 34 publications

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“…A similar model system has been also studied by Zhang and Archer [14] and Sarvestani and Picu [11]. For such a system, molecular simulations [2,10] estimated that a bridging network linking neighboring nanoparticles forms once the wall-to-wall distance between nanoparticles, d w , approximated by [18] …”

Section: Terminal Relaxation Timementioning

confidence: 99%

“…Needless to say, the sum of these probabilities is one. We proceed by assuming that, under equilibrium configuration, these quantities are known or can be determined by molecular dynamics simulations [10,29]. Now let n B and n L be the average number of bridges and loops per chain, respectively.…”

Section: Diffusion Of An Attached Chainmentioning

confidence: 99%

“…The authors recognized that a further refinement of this model is possible by taking into account kinetics of adsorption-desorption, adsorbed layer thickness, conformation and molecular weight distribution. Sarvestani and Picu [10] proposed a network model for nanofilled polymeric mixtures in the unentangled regime and in which the wall-to-wall distance between nanoparticles is on the order of the chain size. The resulting model captured the main features that distinguish nanocomposite and microcomposite behaviors, for example, the enhanced reinforcement at low deformation rates.…”

Section: Introductionmentioning

confidence: 99%

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A reptation-based model to the dynamics and rheology of linear entangled polymers reinforced with nanoscale rigid particles

Kabanemi

Hétu

2010

Journal of Non-Newtonian Fluid Mechanics

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A reptation-based model to the dynamics and rheology of linear entangled polymers reinforced with nanoscale rigid particles Kabanemi, Kalonji K.; Hétu, Jean-Francois Contact us / Contactez nous: nparc.cisti@nrc-cnrc.gc.ca. is its reptation time in the neat polymer, ad is the fraction of attached monomers per chain, and N is the number of monomers per chain. Hence, the overall relaxation is extremely retarded by attractive nanoparticles in the limit of strongly adsorbed chains. Also, it is found that the effective reptation time, d,eff , can be controlled through five main parameters, i.e., the molecular weight of the polymer chain, N, the size of the nanoparticles, d f , the density of attractive site on the nanoparticle surface, n as , the monomer-nanoparticle energetic interaction, ε, and the nanoparticle volume fraction, f . The nonequilibrium dynamics of detachment/re-attachment of monomers from/to nanoparticle surfaces under flow conditions is incorporated in the model to elucidate the effect of monomer-surface interactions on the nonlinear viscoelastic behavior. The resulting model correctly captures the linear dynamical properties and shear rheological behaviors of nanocomposite systems studied. Under very slow shear flow conditions, these filled systems exhibit a strong non-Newtonian behavior and a large enhancement in the viscosity as a certain number of monomers in the chain are attached to nanoparticle surfaces, while at very high shear rates, the neat polymer dominates the shear thinning behavior, suggesting that addition of nanoparticles contributes negligible to the viscosity in strong flows. A picture that is based on transient polymer-particle surface interactions, i.e., the detachment/re-attachment dynamics of monomers from/to nanoparticle surfaces is proposed to interpret the observed huge alteration in rheological properties. Crown

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Section: Terminal Relaxation Timementioning

confidence: 99%

Section: Diffusion Of An Attached Chainmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A reptation-based model to the dynamics and rheology of linear entangled polymers reinforced with nanoscale rigid particles

Kabanemi

Hétu

2010

Journal of Non-Newtonian Fluid Mechanics

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“…For steady shear flow, model predictions and experimental data were in good qualitative agreement, especially for PNC with low nanofiller content. Sarvestani and Picu [2004] proposed a molecular network model of nonentangled polymer matrix with less than 10 wt% of nanofiller particles. The model assumed the creation and destruction of loops, tails, and bridges between nanoparticles.…”

Section: Is a Characteristic Relaxation Time (Assumed To Be Constant)mentioning

confidence: 99%

Rheology of Polymers with Nanofillers

2010

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“…How do molecular clutches know the difference between a fibrous substratum and a continuous substratum of the same stiffness? The key is that fibrous mats and Maxwell-Wiechert viscoelastic continua differ in their loading responses (23)(24)(25): both scenarios typically present concave-down force-displacement relationships in response to a first loading (Fig. 1), but only the fibers within the fibrous mats can be easily modified locally by the cells in a way that changes their local stiffness.…”

mentioning

confidence: 99%